Well, there's this one : Hostile Takeover (http://www.sinful-desire.org/archive/viewstory.php?sid=2114&warning=5)
Summary: COMPLETE. Eight years ago, Jensen and Jared met as they competed for places on the US Olympic Fencing Team and fell in love. Until Jensen broke things off with no explanation three years later, a decision he regretted as soon as he’d done it. That was five years ago, and since then, Jensen and Jared have each taken over leadership of their family businesses. Suddenly CEO Jared doesn't know why Jensen is trying to take over the Padalecki Group, a company Jared’s great-grandfather started. What Jensen really wants is Jared back. Can Jensen convince Jared to give him a chance to prove he’s not the same man who broke Jared’s heart?

I don't know whether it's the one you're looking for since I haven't had time to read this one yet, but it seems kinda similar.

Oh, and some of my favourite CEO fics where Jensen is a dick at first:

Games and Dreams (http://inkbymidnight.livejournal.com/7712.html) (This is a WIP but the author says she's going to complete it when she has time).
Summary: Jensen is a rich, spoiled, commitment-phobic billionaire. Then his entire fortune rests on finding and marrying the perfect guy in the short span of two weeks. Jared is a quiet, hardworking intern and a chance meeting with Jensen throws his careful life into chaos. Jensen thinks his troubles are over after the wedding, little does he know they've only just begun. Because Jared? Can't stand Jensen and doesn't want to have anything to do with him.

The Billionaire's Reluctant Husband (http://archiveofourown.org/works/205608/chapters/305518?view_adult=true/)
Summary: Billionaire Jensen is a playboy and he needs a husband pronto if he wants to keep his company and his inheritance. After a chance meeting with quiet and hardworking Jared, Jensen decides that he’s found the perfect candidate. The arrogant Jensen thinks he’s got Jared in the bag, but when his new husband refuses to sleep with him and doesn’t really even seem to like him, Jensen convinces himself that he’s happy with his open marriage lifestyle. But Jensen becomes increasingly obsessed with his new husband and discovers the truth behind Jared’s dark past.

UGH that first one sounds great but I cannot do WIPs -__-; I devour stories... WIPs are non-confusive to such endeavors.

Thanks for the recs tho. :)

No, that's not it, but I'm definitely saving it :3

some self-pimping, if you don't mind. i wrote a big bang in the same vein a couple of years ago.

be kind, unwind (http://fairly-tales.livejournal.com/12242.html)
jensen ackles is a project manager at ferrisinc, a pr-company, who'll stop at nothing to be the best. as a result, everything he does is calculated and measured, right up to the time it takes for him to have sex with his ex-girlfriend danneel.

in an attempt to make him unwind a little bit, his colleagues convince him to go to a spa and get a few relaxing massages. jensen thinks it's a complete waste of time until he manages to get in with jared padalecki, the most sought-after massage therapist at the spa.

when jensen starts wondering why he responds so well to jared, things get complicated. add to that a womanizing colleague without internal filter and a loudmouth artist with the tackiest designs since the early nineties, and jensen's carefully designed life starts falling apart completely.

you can find a pdf-version in the author's notes, if you're interested. :)

Oooh, sounds good. Nothing wrong with some self-pimpage! And PDFs make my life <3

Is it sad that this line "right up to the time it takes for him to have sex with his ex-girlfriend danneel. " is what makes me want to read it? XD

not at all! it's my fic, so any reason for you to read it, is a good one for me. :) i have no shame.

seconding your fic, it's good :)

I wrote a CEO Jensen where Jensen was kind of hard to get along with until Jared signed on as his personal assistant.

The Tampa Connection (http://tcs1121.livejournal.com/15796.html) was written for the SPN MeantToBe Challenge 2011 (http://spn-meanttobe.livejournal.com/) so it's Harlequin-esque and NC-17 but you might enjoy it.

Prompt Title and Summary: On paper, Jared Padalecki Morgan had a lifestyle most people would envy. Only he knows what a sham his marriage really was. So when his politician husband is killed in a hit and run accident, he moves to Florida and takes a job as a personal assistant to Jensen Ackles, a powerful CEO with an intimidating reputation.
Jared's intelligence and social grace prove invaluable to Jensen, and on a business trip to South Carolina's lush Low Country, their business relationship takes a sensual detour. But when threatening letters arrive at Jensen's office, Jared realizes that his husband's death was no accident—and that he will meet a similar fate unless they can uncover the scandalous truth together...

Intriguing. I might just have to read this one. Thanks for the rec!