Despite the ever-dawdling and presently unnerving Spanish economy, Banco Santander (NYSE: STD) is making its presence felt internationally with an aggressive acquisition strategy. Santander, Spain's largest lender, has beaten out European rivals like BNP Paribas and PKO BP to win Polish regulatory approval for its takeover of Bank Zachodni WBK.

The Spanish giant has offered 16.6 billion zloty ($5.7 billion) to acquire a 100% stake in the Polish bank, which until now had been controlled by wayward Irish bank Allied Irish Banks (NYSE: AIB).

Polish vehicle to success
Right now, Santander holds a strong footing in fast-growing Brazil and austere-but-stodgy Britain -- two crucial areas from which to grow larger. This new acquisition should enable the bank to penetrate further into other markets in the long term. In the short term, it gets Santander into Poland, Eastern Europe's biggest market.

After striking deals with Royal Bank of Scotland (NYSE: RBS) and Skandinaviska Enskilda Banken AB of Sweden, Santander has decided to get its hands on Zachodni to begin pushing into attractive Eastern European markets. Allied Irish, which owns 70 percent of Zachodni, will receive nearly $4.22 billion in badly needed capital from this deal, which also includes a 50% stake of the Polish bank's BZ WBK AIB Asset Management arm. On top of existing market rates, Santander is paying a premium of approximately 6.4% on Zachodni's average share price three months prior to the tender offer. That bonus should secure the deal going forward, especially considering Allied Irish's desperation for capital.

Patience will pay off
Banco Santander seems to be in the right place at the right time, with fresh capital. Its strategic plans and demonstrative aggression also make it look promising.

Relatively speaking, Eastern Europe is holding up well, and it should be an appealing destination for long-term banking activities. This should be music to Santander shareholders' ears.

However, if you're expecting a high return in a shorter period of time, you may have to wait until the deal finishes its teething period. Large-scale acquisitions like this one take time, and for a while at least, the premium Santander paid for Zachodni's shares may not seem worthwhile. But in time, thanks to a few smart acquisitions today, I suspect we'll see Santander join the ranks of other global banking giants.

Fool contributor Zeeshan Siddique does not own any of the stocks mentioned in the article. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.