After last year's dramatic stock-price increases, which have been followed by similar performance year to date, many energy companies are announcing stock splits to make their shares more affordable, thus broadening the shareholder base and increasing trading liquidity. Even after a split, the stocks may continue to climb this year. According to A.G. Edwards & Sons, the universe of E&P stocks its analysts follow is now trading at the midpoint of its five-year historical valuation based on net asset values and earnings multiples. The news indicates the stocks have more room to climb, assuming commodity prices do not decline. "We look for E&P stock appreciation to be driven mainly by multiple expansion within the large-cap group and by NAV-per-share growth within our small-cap universe," the firm reports. Nexen Inc. expected to split its shares in April. Its last stock-split was in May 1996. St. Mary Land & Exploration and EOG Resources did two-for-ones in March, and XTO Energy did a four-for-three, the company's seventh stock split since 1997. Shell Canada Ltd. has announced a three-for-one, and oilfield-services company Precision Drilling Corp. plans a two-for-one.