MELBOURNE, Feb 21 (Reuters) - Caltex Australia Ltd (CTX),...

MELBOURNE, Feb 21 (Reuters) - Caltex Australia Ltd (CTX), facing the loss of up to 17 percent of its earnings if BP goes ahead with a takeover of Woolworths' petrol stations, said on Tuesday it expects to fill the gap by the end of 2017.

Caltex, which owns one of Australia's four remaining oil refineries, is looking to expand its retailing business through new convenience stores rather than focusing on fuel, Chief Financial Officer Simon Hepworth said.

Woolworths Ltd (WOW) agreed to sell its petrol chain, currently supplied by Caltex, to BP for A$1.8 billion ($1.4 billion) in December in a deal that needs to be approved by Australia's competition watchdog.

Sales to Woolworths make up about a fifth of Caltex's 16 billion litres (4.2 billion U.S. gallons) in annual fuel sales, and analysts have estimated the loss of that business will cost it between A$50 million and A$140 million.

"On an annual run-rate basis, we believe we will have replaced that profit gap by the end of this year," Hepworth told Reuters in an interview, after the company released its annual results.

The wide range in the estimated earnings loss is based partly on whether the Australian Competition and Consumer Commission forces BP to sell any petrol stations and how much fuel BP may have to import through rivals' facilities.

Sydney-based Caltex will replace about A$50 million of earnings before interest and tax with its recent acquisitions of fuel station owners Gull in New Zealand and Milemaker in Australia, Hepworth said.

Caltex reported a 17 percent drop in annual profit before one-offs to A$524 million, roughly in line with analysts' forecasts of about A$519 million, as its refining profit margin fell along with oil product prices.

The company's shares, which have dropped about 16 percent over the past year amid worries over the Woolworths sale, rose as much as 3.3 percent on Tuesday to a one-month high.

($1 = 1.3040 Australian dollars)