* Adjusted profit of $1.07 a share, as expected
* Sales bolstered by ARINC acquisition
* Shares up 1 pct (Adds company, analyst comments, details on acquisition, share price)
April 17 (Reuters) - Rockwell Collins Inc, a maker of avionics and other electronics systems for aircraft, reported a lower quarterly profit on Thursday as income tax expense rose but an acquisition bolstered sales, sending its shares up in early trading.
The company is beefing up its exposure to commercial markets as U.S. defense spending shrinks. Commercial revenues stand to grow because of production of newer airplanes such as the Boeing 787 and Airbus A350.
Net income in the fiscal second quarter ended March 31 fell 8 percent to $148 million, or $1.08 a diluted share, from $161 million, or $1.17 a share, a year earlier.
Adjusted profit of $1.07 a share was in line with analysts' average expectations, according to Thomson Reuters I/B/E/S. The year-earlier results included a tax benefit.
Rockwell last year bought ARINC Inc, a provider of aviation connectivity services including flight planning and high-speed data, and has said that purchase will enable it to offer more information management services for aviation.
Chief Executive Kelly Ortberg told analysts during a conference call Thursday that the ARINC purchase had already paid off with a recent agreement Rockwell Collins signed with British telecommunications provider Inmarsat to provide Ka-broadband service to airlines.
Rockwell Collins said its increased business on new plane programs and rising international sales "more than offset" expected weakness in defense and business jets in the latest quarter.
"The long-term path for growth remains intact given the aerospace cycle ramp and bizjet market share gains kicking in" during fiscal year 2015, Sterne Agee analyst Peter Arment said in a note to clients on Thursday.
Quarterly sales rose 12 percent to $1.27 billion. Analysts had expected sales of $1.25 billion on average.
Commercial system sales rose 3 percent to $556 million, helped by higher sales tied to maintenance and services and increased deliveries of hardware for the Boeing 787. Government-related sales dropped 2 percent to $567 million. Sales in the new information management services segment came to $149 million.
The company said it now expects profit of $4.40 to $4.55 a share for the current fiscal year, compared with a prior forecast of $4.35 to $4.55 a share. It cited better earnings tied to ARINC for the revised forecast. Analysts expect it to earn $4.45 a share for the year.
Shares of Rockwell Collins were up 1 percent at $79.39 on Thursday. The stock has risen about 7 percent this year. (Reporting by Karen Jacobs in Atlanta; Editing by Bernadette Baum)