* Q1 rev beat estimates by $10 mln
* Raises share buyback program
* Q1 adj shr beat estimates by 1 cent
* Sees FY rev flat; Q2 rev flat to slightly down (Adds details, conference call comments)
April 29 (Reuters) - Infrastructure software maker Citrix Systems Inc (CTXS.O) posted a quarterly profit largely in-line with estimates, while revenue beat market expectations by a healthy margin, and it increased its share repurchase program by $300 million.
Shares of the company, which develops virtualization software that allows a single computer to act like many "virtual" machines, were trading up more than 4 percent in after-hours trade.
The company was experiencing a shift in business mix as customers capped expenses and initiated fewer large projects and looked more towards subscription offerings, it said in a conference call with analysts.
In the first quarter, 60 percent of the company's revenue came from subscription services while new licences contributed only 30 percent.
Citrix said it was providing less quantitative guidance than in previous quarters citing low visibility, especially for new licence revenue.
The company said it still expects full-year revenue to be flat and expects second-quarter revenue to be flat to slightly down.
Earlier this month Citrix's main rival VMware Inc (VMW.N) said its second-quarter revenue would dramatically miss estimates due to the weak economy and a new product launch.
First quarter profit fell to $6.9 million, or 4 cents a share, from $34.4 million, or 18 cents a share a year-ago. Excluding items, the company earned 32 cents a share.
Total net revenue fell 2 percent to $369.1 million.
Analysts were expecting a profit of 31 cents a share on revenue of $359.1 million, according to Reuters Estimates.
The company's application virtualization business, its largest revenue earner, fell 10 percent to about $240 million, as lesser million-dollar-plus deals came its way.
Its software services business grew 16 percent, while its fledgling server and desktop virtualization business grew 150 percent.
The company said it reduced headcount by 8 percent in the quarter as part of its ongoing restructuring program.
Shares of the Fort Lauderdale, Florida-based company were trading at $26.80 in trading after the bell. They closed at $25.65 Wednesday on Nasdaq. (Reporting by Sayantani Ghosh in Bangalore; Editing by Savio D'Souza)